WordPress removes the Update Services ability (Settings – Writing) when you create a network (aka enables WordPress MU/Multisite).
Activate this plugin to get it back.
Note: This is only for WordPress setups with a network, aka multiple sites, aka multisites,
aka WPMU in WordPress 3 and later.
This plugin might work with older WordPress MU sites. I haven’t tested it though. If you do, please
let me know how it turned out.